Work rest for centerless grinding machines



Mas' 22, 1951 s. s. sMpLicH v 2,554,423

WORK REST FOR CENTERLE'SS GRINDING MACHINES Filed Jan. 29, 1948 Patented May 22, 1'951 UNITED STATES PATENT OFFICE WORK REST FOR CENTERLESS GRINDING MACHINES This invention relates to centerless grinding machines and particularly to a device for producing and maintaining concentricity when grinding on a centerless machine.

Centerl'ess grinding machines are primarily used for grinding the outer surfaces of cylindri- 4 cal members by merely locating the work to be ground by its outer peripheral surface. My invention` provides a novel and improved work blade which is mounted in the conventional manner on such a machine but which will axially position the work to maintain and produce concentricity thereof during the grinding operation.

it is an object of my invention -to provide a de- -vice adapted to be attached to a centerless vgrinding machine to hold and axially support a work piece for concentric grinding thereof.

It is another object to provide a work supporting member adapted to be mounted on a centerless grinding machine to initially support a work piece between the grinding and regulating wheels and being adapted to thereafter progressively shift said work piece toward said regulating wheel to maintain contact therewith during the grinding operation.

It is still a further object of my invention to provide a work blade having a pair of work receiving slots formed therein and adapted to be interposed between the grinding wheel and regulating wheel of a centerless grinding machine with said slots sloping downwardly toward said regulating wheel and adapted to axially receive and support a work piece therein to progressively shift the same toward said regulating wheel to maintain Contact therewith during the grinding operation.

These and other objects and advantages of my invention will more fully appear from the following description made in connection with the accompanying drawings wherein like reference characters refer to similar parts throughout the several views and in which:

Fig. l is a side elevational view or a conventional centerless grinding machine showing my work blade mounted thereon for concentrically grinding a work piece therein;

Fig. 2 is a top plan view showing the relation of my work blade with a work piece supported therein and the grinding and regulating wheels in grinding position;

Fig. 3 is a side elevational View of one form of work blade embodying my invention;

Fig. 4 is an end elevational view of the work blade shown in Fig. 3;

Fig. 5 is a perspective View Of 2 Second form of my invention; and,

Fig. 6 is an end elevational View of the work blade shown in Fig. 5.

A conventional centerless grinding machine such as the Cincinnati Number 2 Centerless Grinding Machine made by the Cincinnati Grinders, Inc., Cincinnati, Ohio, is illustrated in Fig. 1.

This machine has a base I0 with a supporting structure II mounted thereon. A rotary grinding wheel I2 is journaled on said supporting structure I I for rotation on a transverse horizontal axis and has an adjustment mechanism I3 attached thereto. This rotary grinding wheel I2 is made from any suitable abrasive material and suitable power means are provided for driving the same at high speeds. Longitudinal ways Ifl are mounted on supporting structure I I. A lower slide I5 is slidably mounted on said ways i4 for longitudinal shifting movement thereon and there is a suitable mechanism provided for progressively shifting said lower slide I5 on said ways I4 and operating control lever I5 actuates this mechanism and controls the rate of shifting movement of said lower slide I5. An upper slide I'I is slidably mounted on lower slide I5 and has a regulating wheel I8 journaled thereon for rotation on a horizontal axis disposed substantially parallel with the axis of rotation of said grinding wheel. A suitable regulating wheel adjustment mechanism I9 is attached to said regulating wheel for truing and adjusting the same. Clamping means are provided on the upper and lower slides and are respectively operated by the upper slide clamping lever 20 and the lower slide clamping lever 2|. Suitable mechanism, operated by the hand wheel 22 is provided for moving the upper slide I1 on lower slide I5.

A conventional transversely disposed work rest 23 is attached at the forward end of slide I5 as by a dovetail mortise and tenon joint. rIhis work rest 23 is adapted to receive a transversely extending work blade at the top thereof and to securely clamp the same in iiXed relation thereto for movement with said lower slide I5. The foregoing description includes the related elements of the conventional` centerless grinding machine illustrated in Fig. 1.

A work blade embodying one form of my invention and designated by the letter A is illustrated in Figs. 3 and 4.

A block 24 forms the lower portion of form A of my invention and has a pair of longitudinally disposed vertically spaced and vertically aligned parallel openings 25 and 26 bored therethrough. The central portion of the block 24 is cut-away a-slight distance above the bottom thereof forming a recess adapted to receive a work support 21 therein. The work support 21 has a pair of vertically spaced parallel openings 23 and 2B respectively bored therethrough and said openings 28 and 29 are adapted to be respectively aligned with openings 25 and 2S. A shaft 3E of such size as to closely fit within the aligned passages 25 and 28 is` inserted therethrough tov-,pivotally connect saidffworksupport 21 with blockjZd, the :close fit of shaft 33 preventing play in the connection. Slightly yieldable means are provided for connecting the intermediate portions `of the work support 21 and block 24 such Aas Athe#extremely high tension spring 3| inserted into the aligne-d openings 26 and 29 and having fretainingpins-r32 at the respective ends thereof for `holding said spring 3| in tightly stretchedf'position withinf'said openings. The top portion of the workgsllpport 21 is cut away to form a work receiving recess .3.3 anda pair` of lopposed shaft receiving `slots 34 are formed at the respective ends of recess 33.

These slots 31S slope outwardly Yatthe bottom v,thereof as besty shown in1Fig.-4. Thepurpose for M,this slope will hereinafter Vbecbrought out-,and .is extremely important to thesuccessful operation of my invention.

The operation of form,-A.of. my invention is as follows. The block 2.4fis initially clampedjin .the ,workrest 23and extends Vupwardly therefrom into position between the ,grinding wheel I2 -and the regulating vwheel .I 8. The vlower side .is then clamped ,by setting nclamping lever 2l and `the ,regulating wheel shifted toward said grinding wheel and into closely spaced relation to work ,.blade A. 'The -Work blade A is vplaced ,in work )$6513.23 sothat theslots34 s'lopeftoward the regujlating wheel i8. A work piece such as .the rotor A35illustrated in Fig..2 with ashaft ZSeXtending therethrough in substantially concentric ,relation .thereto is placed in recess 33 .With the end .portions of thecshaft 3,6 respectivelyreceived in the ,..Slo1ts'34,.the slotsd 'being of .such size as .to closeflyft vwith the end portions of shaft36 and Vjour- AVnal the same for `steady rotation therein. The Awork piece 3 5 .is engaged by theregulating wheel [B as 'the same is shifted towardsaid grinding whee1 and the regulating .wheel is shifted far enoughto hold theshaftj3 inthe Yupper portions of theslots 34. The upper slide clamping lever `is then locked iand the regulating wheel rotated at a .relativelyrslow speed, suitable driving Ymeans for the slow speed rotation of rsaid regulating wheel being provided. The contact betweenthe periphery of the work piece and the Vregulating wheelinitially.drivessaid work piece ina Acounter-clockwise direction as viewedinFig. 1. The grinding wheel as well as the .regulating wheel 'is rotated ,in a ,clockwise direction; With ythe work piece 35 `in drivingContact with the regujlatllg wheel, thestop lever 42l for the lower `slide vis releasedand the lower slide including the regulating wheel land `work .piece 35 mounted in work support .21 are moved asa unit towardsaid grinding wheel I2 by pulling downon lever I6.

As ,the grinding wheel reduces the size of the part being ground, saidpart .will slide downwardly 1n thesloping .slots 3:3 and Vcontact with the regulating wheel will .thus vbe maintained. The spring-3| is strong enough to prevent -pivotal movement of the worksupport .21 and to hold the work piece .in driving vcontact with the regulating wheel with sufficient force lto maintain the part in the fupper portion -of the slots 34. c'However, if -.the initial sizeof lthe part being ground Should he so large that it reaches the bottom -of the slots 34 before the grinding thereof is complete, then and only then, will the pivoted work support 21 be swung about shaft 30 as an axis. If the part reaches the bottom of the slots 34, contact with the regulating wheel will be maintained by the pressure on lever IB forcing the part against the grinding wheel which in turn applies a reacting force .whichrnoves thepart Yback toward therregulating wheel and swings the upper portion of the work support 21 a slight distance steward the regulating wheel against the resilient ,force of spring 3i. With the normal adjusted ','setti'ng'of'the wheels I2 and I8, the work will tend to be drawn therethrough; therefore, I have Yfound,it-:advisable to provide an end stop 31 as best shown in Fig.,3 to prevent longitudinal displacement ofthe 'shaft 36 during the grinding operation. As soon as the part is ground to the desired size, the handle I6 is released and the lowerslide lwillcmove away from the grinding wheel .and the part may `be easily removed .from ,the slots-and a new part inserted therein without subsequent .adjustment of .the spaced relation ,betweenthe peripheryiof the new part andthe .regulating wheel. lt is extremely Veasy Vand Va. Ahigh degree of speedcan be .obtainedby'inserting partsinto an open topped groove or slot such as the slots 34.

The .vertical position of the shaft 35 within slot .34 before the grinding operation is begun will be .slightly below the topof the slots Hand need not be in anyrvparticularv position'within said slots-.34. .In the removal-of the part from the slots 3Q, the slope `of said slots will guide the part away from vthe regulating wheel as said part is raised-therein.

Also, in the normal grinding-procedure for an `operation such as this, the part tobe ground vshould. be located slightly above Ya plane through -:the substantially parallelaxes o'f rotation of the .grinding and regulating wheels I2 vand 'I8 respectively. This position lofthe part will alsoitend in lcombination lwith the lsloping slots '3d to progressively provide more clearance between the part and the regulating `wheel *as lit is v'raised to beA removed.

Form B of my invention isillustrated in Figs f5 and 6 and an integral solid Work blade vfis aprovided. This solid work blade B has the sloping' slots V38 which are substantially the lsame as the slots 34 and which voperate in a similar manner to said slots 3d. The block Band slots 38 thereof are placed in xed relation relative to regulating -wheel I8 when the 'lower slide l5 is securelylocked to the upper slide rI1 by clamping lever 23. The operation of form B of my invention -will vbe exactly the same as form .A of'my invention, as previously described, until the shaft 36 of the Work piece .35 reaches the bottom' of the 'slots 3S. AAt this point, any further grinding von the periphery of the part .will reduce the size of the part ,to prevent contact between the Avpart .and the regulating wheel.

It -will be rseen that I .have provided Van eX- tremely simple, highly efficient work blade -for Va centerless grinding Vmachine mounted in the -conventional Vman-ner thereon vbut having anovel rand'v improved means for .supporting and Yholding a work piece therein to maintain with a -high degree of accuracy Vt-he'cor-icentricity between relative portions of ysaid Work piece during thegrinding-of the work piece. The rotor 35 has Va shaft 36 xed therein but it would A.be an easy "matter f to insert an arbor through a -hollow -Work vpiece ing maintain concentricity between the inner and outer peripheries of said hollow member.

Slots of various sizes may, of course, be used depending upon the amount of material to be normally rem'oved from the parts to be ground and the speed with which said material can be ground.

The angularly sloping slots perform two functions. One is to displace a part being ground toward the regulating wheel of the grinding machine to maintain contact therewith during the grinding operation. The amount of actual displacement toward said wheel during the grinding operation will be exactly equal to the normal reduction of the radius of the part being ground. The other function of the sloping slots is to permit extremely easy and quick removal of the part after completion of the grinding operation and thus materially increase the speed with which a large number of parts may be successively ground on a grinding machine.

It will, of course, be understood that various changes may be made in the form, details, arrangement and proportions of the parts without departing from the scope of my invention.

What I claim is:

l. A work supporting member for centerless grinding machines of the type having a supporting structure, a rotary grinding wheel journaled on said structure with means for driving the same, a rotary regulating wheel journaled on said structure in opposed spaced relation to said grinding wheel, means for driving said regulating wheel, and means for controllably varying the spaced relation between said wheels; said work supporting member comprising a work blade adapted to be xed in various predetermined relations to one of said wheels, said work blade having a pair of opposed spaced .parallel slots formed therein and directed downwardly and sloping inwardly toward the wheel mounted in fixed relation thereto, said slots being adapted to receive a trunnioned work piece therein and permitting said work piece to be progressively shifted toward said last mentioned wheel as material is ground from said work piece during the grinding operation.

2. A work supporting member for centerless grinding machines of the type having a supporting structure, a rotary grinding wheel journaled on said structure with means for driving the same, a rotary regulating wheel journaled on said structure in opposed spaced relation to said grinding wheel, means for driving said regulating wheel, and means for controllably varying the spaced relation between said wheels; said work supporting member comprising a blade carrying block adapted to be fixed at various predetermined relations to one of said wheels, a working blade pivoted on a longitudinal horizontal axis to said block, a highly resistant resilient element connecting said blade to said block and normally resisting pivotal movement on said axis, a work piece support with opposed trunnion receiving and guiding elements directed generally downwardly and inwardly toward one of said wheels whereby said work piece is progressively shifted toward the wheel mounted in fixed relation thereto to maintain contact therewith as the work piece is diminished in size 1 by the grinding operation, said resilient element permitting displacement of said work piece toward said wheel only when said downwardly and inwardly directed elem-ents are rendered inoperative by excessive grinding of the work piece.

3. A work supporting member for centerless grinding machines of the type having a supporting structure, a rotary grinding wheel joui'- naled on said structure with means for driving the same, a rotary regulating wheel journaled on said structure in opposed spaced relation to seid grinding wheel, means for dcriving said regulating wheel, and means for controllably varying the spaced relation between said wheels; said work supporting member comprising a blade carrying block adapted to be xed in various predetermined relations to one of said wheels, a work blade pivotally connected thereto for pivotal swinging m-ovement on a longitudinal horizontal axis in substantially parallel relation to the axis of rotation of said wheels, highly resistant resilient means to normally hold said work blade in substantially fixed relation to said wheel mounted in fixed relation to said block, said work blade having a pair of angularly disposed opposed spaced parallel slots directed downwardly and inwardly toward said last mentioned wheel and adapted to receive a trunnioned work piece for journaling the same therein, whereby said work piece is progressively displaced toward said wheel as it shifts downwardly in said slots to maintain contact with said wheel during the grinding operation, said resilient means yielding to permit pivotal movement of said blade only when the trunnions of said work piece reach the bottom of said slots when more than a normal amount of material has been ground from said work piece thus maintaining contact between the wheels and said work piece.

4. A work supporting member for centerless grinding machines of the type having a supporting structure, a rotary grinding wheel journaled on said structure with means for driving the same, a rotary regulating wheel journaled on said structure in opposed spaced relation to said grinding wheel, means for driving said regulating wheel, and means for controllably varying the spaced relation between said wheels; said work supporting member comprising a work` blade adapted to be mounted in various predetermined precisely fixed relations to one of said wheels, a pair of opposed spaced parallel angularly disposed slots formedvin said work blade to receive a trunnioned work piece therein said sloping slots being directed downwardly and inwardly toward said last mentioned wheel to form the sole means for shifting said work piece mounted therein progressively toward said wheel to maintain contact therewith as material is ground from said work piece during the grinding operation.

SYLVESTER S. SMOLICH.

REFERENCES CITED The following references are of record in the le of this patent:

UNITED STATES PATENTS Number Name Date 1,791,713 Caster et al. Feb. 10, 1931 1,814,361 i Booth July 14, 1931 2,440,402 AI-Iorberg Apr. 27, 1948 

